Data centers and other large computer systems are often centrally managed. However, not all managed nodes necessarily need the same services. Accordingly, central-management software vendors sometimes permit customers to obtain licenses only for the hardware that needs the management features. For example, there would be no need to pay for a license for workload management for a server that runs a fixed workload, e.g., like the central-management server. In such a business model, it is necessary to determine what products are licensed for each server.
One way to keep track of licenses is to install license software and data on each licensed server. When the central-management software polls the managed servers, it can ask all the servers that it discovers to check their licensing status for a given management product. This approach has been extended to systems that include virtual servers.
Virtual-server technology can allow different operating system instances to run concurrently on a single computer system. Each operating system instance interacts with a host virtual-server operating system as though the latter were hardware. For most purposes, e.g., communicating over a network, there is no distinction between hardware servers and virtual servers running on a virtual-server host. Accordingly, license software can be installed on each virtual server on a licensed host so that when the virtual server is polled, it can inform central-management server that it is or is not licensed for a given management product.